"The X-Beam's wider, super-strong crossbeam design increases the wrench's contact area with your hand by 500 over traditional wrenches - you can grasp the wider side of the wrench beam for more power and control with less stress on your hand. Open end features Surface Drive Plus, with reduced fastener rounding and up to 25 more torque. Ratcheting box end needs as little as 5 to move fastener vs. 30 for standard box-end wrenches. Material Type Alloy steel, Storage Type Tray, Ratcheting Yes, Flex Head No, SAE Sizes in. 5/16-3/4, Wrench End Type Open/boxed, Finish Type Full polish chrome, Measurement Type Standard SAE, Pieces qty. 9."